As a part of patch series about wrong trigger register() and get() calls order in the some IIO drivers trigger initialization path: https://lore.kernel.org/all/20220524181150.9240-1-ddrokosov@xxxxxxxxxxxxxx/ runtime WARN() is added to alarm IIO driver authors who make such a mistake. When IIO driver allocates a new IIO trigger, it should register it before calling get() operation. Otherwise, the next iio_trigger_put() will upset refcnt balance. Signed-off-by: Dmitry Rokosov <ddrokosov@xxxxxxxxxxxxxx> --- include/linux/iio/trigger.h | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/include/linux/iio/trigger.h b/include/linux/iio/trigger.h index 4c69b144677b..4a008b952710 100644 --- a/include/linux/iio/trigger.h +++ b/include/linux/iio/trigger.h @@ -93,6 +93,15 @@ static inline void iio_trigger_put(struct iio_trigger *trig) static inline struct iio_trigger *iio_trigger_get(struct iio_trigger *trig) { get_device(&trig->dev); + + /* + * If driver hasn't called iio_trigger_register() before and trig->owner + * wasn't initialized properly, trigger will have wrong number of users + */ + WARN(!trig->owner, + "Ignore module getting for non-registered iio trigger %s\n", + trig->name); + __module_get(trig->owner); return trig; -- 2.36.0
